Ccd type solid-state imaging device

Abstract

A CCD type solid-state imaging device includes plural pixels 2 that are arranged and formed on a semiconductor substrate in a two-dimensional array, plural vertical charge transfer paths 3 each of which extends along a corresponding pixel column formed of the pixels 2 , and a horizontal charge transfer path 4 that is formed along end portions, in a transfer direction, of the vertical charge transfer paths 3 . A physical structure of the horizontal charge transfer path 4 is such a large capacity structure that a signal charge having an amount larger than a maximum amount of a signal charge transferred by each vertical charge transfer path 3 can be transferred.

1 . A CCD type solid-state imaging device comprising:
 a plurality of pixels that are formed and arranged on a semiconductor substrate in a two-dimensional array;   a plurality of vertical charge transfer paths each of which extends along a corresponding pixel column formed of the plurality of pixels; and   a horizontal charge transfer path that is formed along end portions, in a vertical transfer direction, of the vertical charge transfer paths, wherein   the horizontal charge transfer path has a physical structure in which a signal charge having an amount larger than a maximum amount of a signal charge transferred by each vertical charge transfer path can be transferred.   
   
   
       2 . The CCD type solid-state imaging device according to  claim 1 , wherein
 the physical structure of the horizontal charge transfer path determines a transfer capacity of the horizontal charge transfer path, and   a physical structure of each vertical charge transfer path determines a transfer capacity of each vertical charge transfer path.   
   
   
       3 . The CCD type solid-state imaging device according to  claim 2 , further comprising:
 a charge temporarily storing section that is provided between the end portions, in the vertical transfer direction, of the vertical charge transfer paths and the horizontal charge transfer path, wherein   the charge temporarily storing section has a buffer area corresponding to each vertical charge transfer path,   the charge temporarily storing section temporarily stores the signal charge transferred by each vertical charge transfer path in the corresponding buffer area, and transfers the temporarily stored signal charges to the horizontal charge transfer path, and   a capacity of each buffer area is an intermediate capacity between a transfer capacity of the horizontal charge transfer path and a transfer capacity of the corresponding vertical charge transfer path.   
   
   
       4 . The CCD type solid-state imaging device according to  claim 1 , wherein the horizontal charge transfer path is configured to be able to transfer the signal charge having the amount being equal to an integer multiple of the maximum amount of the signal charge transferred by each vertical charge transfer path. 
   
   
       5 . The CCD type solid-state imaging device according to  claim 3 , wherein assuming that that the transfer capacity of the vertical charge transfer path is equal to 1, the capacity of the buffer area is equal to 2 and the transfer capacity of the horizontal charge transfer path is equal to 4. 
   
   
       6 . The CCD type solid-state imaging device according to  claim 1 , further comprising:
 a horizontal drain that is formed along the horizontal charge transfer path; and   potential barriers that are provided between the horizontal drain and the horizontal charge transfer path and are provided for all transfer stages of the horizontal charge transfer path, wherein   the potential barriers are formed to be high an unevenness caused by a fabrication process.   
   
   
       7 . The CCD type solid-state imaging device according to  claim 6 , wherein of the potential barriers, a potential barrier for a first stage of a portion, for transferring charges detected by an optical black portion, of the horizontal charge transfer path is formed to be lower than potential barriers for stages of the portion of the horizontal charge transfer path that are disposed on a downstream side of the first stage in a horizontal transfer direction. 
   
   
       8 . A CCD type solid-state imaging device comprising:
 a plurality of pixels that are formed and arranged on a semiconductor substrate in a two-dimensional array;   a plurality of vertical charge transfer paths each of which extends along a corresponding pixel column formed of the plurality of pixels;   a horizontal charge transfer path that is formed along end portions, in a vertical transfer direction, of the vertical charge transfer paths;   a light shield member that divides the pixels into (i) pixels in an effective pixel area and (ii) pixels in an optical black portion provided on an upstream side in a horizontal transfer direction of the horizontal charge transfer path;   a horizontal drain that is formed along the horizontal charge transfer path; and   potential barriers that are provided between the horizontal drain and the horizontal charge transfer path and are provided for all transfer stages of the horizontal charge transfer path, wherein   of the potential barriers, a potential barrier for a first stage of a portion, for transferring charges detected by the optical black portion, of the horizontal charge transfer path is formed to be lower than potential barriers for stages of the portion of the horizontal charge transfer path that are disposed on a downstream side of the first stage in the horizontal transfer direction.